Distorted TX DAX audio

Greg - KØGDI

Thanks for this.  I used part of this script to create my own batch file so I don't have to deal with resetting DAX everyday.

Bob2 K2DRH

Flex 6700 with ver 1.11.2, purchased at Dayton 2016
(no point in paying for a software version I can't use with a DSL internet connection).  

I had noticed that other stations that should have heard me loud and quickly (I run a big 8x7 6M array and high power) were not decoding me as often as they normally do.   This morning while working WSJT MSK144 I turned on the RX audio so the TX audio monitor would work (I don't often listen to audio when I do digital) and heard the audio stream on the monitor sounded distorted similar to being over driven (ie too much audio gain). My CW ID sounded like it had an echo and it all ran together. 

I checked the TX Stream level and it was at the normal setting, cut it back then restored it and it responded correctly on the P/CW window's level meter (I run it flat EQ, no compression in DIGU mode).  I tested it with another station and he said it also sounded distorted and was not getting decodes commensurate with the strength and frequency of my signal bursts.  Another station was SWL and said the same. 

I have three computers running DAX (I often run WSJT or N1MM off different networked computers than the Flex - sometimes I run the Flex on the Maestro), all of them had the same MSK144 TX audio distortion in the monitor when they went to DAX TX.  I then brought up N1MM and tested the voice keyer. It was horribly distorted in both the monitor and over the air on all three computers.  So I tried rebooting the SmartSDR program.  Same problem.

Since the three computers all have different instances of DAX and WSJT running (as well as use different com ports and slices to the DAX RX/TX), the only other thing in common was the radio itself,  So I did not reboot DAX, but rather power cycled the radio with the front panel switch and reconnected.  Bingo - all working normally again per the monitor.  The other stations I was testing with got solid decodes again too and one said that the over the air audio from the N1MM voice keyer was normal. I never had to stop/restart DAX on any machine.
 
I was on N0UK Ping Jockey chat at the time and noted my experience with the DAX.  I immediately got back 2 replies from other stations indicating similar problems with distorted DAX TX audio that had occurred for them.  They both said they had solved the problem by closing and reinitiating DAX.  One told me he had had the problem with previous versions of DAX and SmartSDR too. I see now that others in the community have had this problem and all seem to solve it by reinitiating DAX. My experience was different,  I had 3 instances of DAX running and shutting down the radio then rebooting it solved the problem for all three.

Hope this helps you find and solve this long standing problem.
73 de Bob K2DRH

Cal N3CAL

Just wanted to let Flex know this issue still happens with latest SSDR Software Version 2.1.33!    In the past 5 weeks my new 6600 has had the TX distortion several times while running WSJT-x FT8 Mode.  Closing DAX and restarting the DAX software corrects the issue.    Any updates on fixing this bug #2391???   Cal/N3CAL

Picture of Distorted TX Signal:



Picture of normal TX Signal:

Greg - KØGDI

I'm still waiting on this issue to be fixed.  I had to reset DAX multiple times a day otherwise it gets distorted. 

NM1W

Yep known issue that dax gets both xmit and rcv corruption....Makes dax a pita on the 6700..   even one dax stream cant avoid corruption after a period of time... Clearly its not something flex is interested in addressing... 

Bill -VA3WTB

Why is it clearly something they don't want to address?

Bob2 K2DRH

Like NM1W says Its not only TX.  I notice that after a few hours of monitoring FT8 on 6M the traces from received stations in WSJT-X wide graph get fuzzy and distorted and cease to decode.  Closing then restarting DAX corrects this and they decode again.  Really is a PITA and should not happen .. why is this so hard to fix?

Bill W2PKY

Hello Bob2-

I have the Asus Z97A I7-4790 board that will not run DAX [receive] reliably on Win10; However, just fine on Win7 Pro. The transmit buffer does get corrupted if the radio runs for 24 hours or more.

My two Surface Pro tablets will run DAX [receive] just fine on Win10 Pro. Have not checked for the transmit buffer issue on the Surfaces. 

So it seems the receive problem may be hardware related, at least in my case. Any chance you can try a different computer or go back to Win7?

This have been discussed many times before. 

Bob2 K2DRH

Yes I see that it has Bill TU. 

I've also discussed it with other Flex owners outside these forums.  Tried it on 3 computers with similar results all Win10.  I do leave my radio and computers both on for extended periods to monitor 6M FT8 when I am not in the shack and now understand that not rebooting for days at a time probably contributes to the problem.   

Ian1

I had this problem for a very long time and on occasion it still occurs. I found the best thing in my case was not to allow Dax or Cat to auto load that has stopped most of the issue. But on occasion Dax will get corrupt and i just close Dax and restart it and i am fixed. This issues has went on for years look up Dax corruption. Ian Km4cqg

Bill AB7AA

I've had the problem just as described for years with my 6700's and even when I had a 5000.  I believe that I've always run Win7 Pro, even with the 5000.  I leave the radios on 24/7.

Frederic HB9CQK

We have to differentiate the TX from the RX DAX corruption issue! The thread title indicates TX only while several users are reporting RX issues. I have had RX DAX corruption issues for several years. Just like Ian reports it comes, goes away, but comes back again.

I had an intense support session with Neil from FlexRadio support on this issue. We started with getting rid of DPC's (I had DPC's caused by the nvidia grafics drivers) but that did not help at all. I updated all the drivers and the BIOS - still the same. The PC is a fast ASUS ROG with 7th generation i7 and 32 GB of memory. Processing power is not an issue. I can DEFINITELY influence the occurrence (it happens between several times a day to once a week) by disconecting/connecting USB devices. I got rid of a creative USB sound blaster that I used to interface my IC-7800 with. Things improved, but DAX corruption is still there. I am still in the debugging process. It is very difficult to say if a measure helps or not because it may take a long time for the problem to show again.

I attached two pictures to show you what I see as RX DAX corruption: On the first picture FT8 waterfall traces become fuzzy and the spectrum looks like it went through a low pass filter. Nothing gets decoded in that state. The second pictures is a comparison between my FLEX-6700 and my IC-7800. on 20m FT8. You can see that the waterfall traces on the 6700 become fuzzy, while the IC-7800 is OK.

When I reset DAX (I use the batch file from Cédric, HB9HFN) all is fine, until corruption occurs again. If you have any hints on what else I could try (short of a complete Windows 10 clean install) please let us know! This issue has cost me countless hours.

Thank you very much and 73, Frédéric, HB9CQK

Asher - K0AU

Cal N3CAL

James Skala

Yes it still exists. I wish it would get fixed!

NM1W

Still waiting for a fix.... its a regular pita

Asher - K0AU

K9DUR

James Skala

In my case, I would disagree with the High DPC's.  I worked with Flex, ran all the tools and the problem at hand is much more then that.  When I opened up this thread I supplied all the information which does not show itself as DPC related.


I run a 24 x 7 remote and about every 2 days I have to start and stop DAX.  Peak at the data I provided.


In my opinion this problem is very complicated or it would have been fixed by now.

It has been around since SmartSDR came out.  

I even had this problem with my 6300.

I have been very patient, and feel bad for the SmartSDR developers but some point they are going to have to fix the problems that have been hanging around.

KY4JLS

James

Grant Saviers

Can this be a problem in the radio?  My 6700/Maestro TX FT8 badly distorts after 2 or 3 days of power on.  A reboot of the radio fixes the problem.  Perhaps this resets DAX, It shows as running all the time and I do not restart it.  The reconnect is automatic with the radio only reboot and Maestro reconnect sequence.  I'm very suspicious of a memory leak or calibration routine drift.

K9DUR

Restarting DAX will fix it. No need to re-boot the radio. Do you leave the client running 24/7? If not, use the option to start/stop DAX along with the client. That is what I do with my 6700 & have not had a problem since that feature was added. — 73, Ray, K9DUR

roger na4rr

This is a real PITA.  Just about all my on air time for the last few months has been FT8.  I have gone from an ft8 hater to ft8 lover.  Lot of good dx on 17m.  The bad part is all of a sudden I cant get a contact and no answer to my cq.  Then I look at my signal and its a piece of garbage. Most of the time start and stop of dax will fix but some sometimes I have to restart the radio and.or SmartSDR.  Maybe its time to start a gofundme page so FRS can hire a programmer with the ability to fix the problem.  In the mean time I just use use the ICOM 7100 in the RV.  It never misses a beat.

Bob Crowley

Just so you don't feel too bad, my ANAN 8000dle on Win10 has the same problem running WSJT-X over VAC. It has been a problem that appears independent of the PC used (have tried two different, powerful machines) and no matter what settings I use for data transfer in the SW which is HPSDR.  I was starting to suspect the WSJT-X software and when the new version came out very recently was disappointed in some respects that nothing had changed. I also have a 6400M and will run it on a MAC OS machine with WSJT-X and see if the same phenomenon is present.  It sure is a show-stopper and I nearly resorted to using two sound card USB dongles back-to-back, but I haven't gotten that desperate, yet. Fingers crossed for the 6400 on a MAC.

Asher - K0AU

Tim, VK6EI

Tim,

without having to troll through the many many posts about DAX Audio distortion are Flex still going to look at the issue or has it been put in the too hard basket? FT8 for me is useless, within a couple of seconds of transmitting the audio distorts and sounds like some have fired up an over driven electric guitar.

Apologies for replying to a 3 year old thread!

73

Tim, VK6EI.

David Decoons, wo2x

Tim,

What version SmartSDR DAX are you using? I believe it was in 2.6/3.1 versions that the DAX drivers were updated.

I am running 3.1.8 without issues. 

How about latency on the PC? DPC Latency Monitor can help determine if there is something (program/driver ) causing major interrupts.

It is always good to post software and OS versions you are running so that others can better assist you.

Dave wo2x

Tim - W4TME

@Tim, VK6EI - we are actively working on the DAX driver corruption issue

dj0op

DAX Corruption Solved (For Me)

I was able to solve my DAX (WSJT-X) corruption issue some days ago. It was a DPC issue caused by malware "searching for advertising".
Totally solved my issue after using malwarebytes prog "adwcleaner.exe", and moving the "result" to quarantene.
Also the delays when loadin cw-skimmer-server are gone.

73 de Henry (dj0op)

David Decoons, wo2x

Nice work Henry!

73 Dave wo2x

Mike-VA3MW

Nice one Henry

You can start to see DPC issues if you are running FT8 and you look at your DT numbers. If they start going longer than 0.5 seconds and then start hitting 1 second, it means your computer is way too busy and it can't do the FT8 decoding fast enough.

It is a good indicator or PC performance.